Exhaust hood



J. HYDE EXHAUST HOOD Oct. 3, 1967 2 Sheets-Sheet 1 Filed July 15, 1965 RE mm m r W w dlliarne q J. HYDE Oct. 3, 1967 EXHAUST HOOD 2 Sheets-Sheet2 Filed July 15, 1965 VIII/1 1149 INVENTOR. JACK HYDE Omar-22g UnitedStates Patent 3,344,775 EXHAUST HOOD Jack Hyde, Pittsburgh, Pa.,assignor to Koppers Company, Inc., a corporation of Delaware Filed July15, 1965. Ser. No. 472,229 11 Claims. (Cl. 122-7) ABSTRACT OF THEDISCLOSURE An exhaust metallurgical hood comprises a reticular frame offluidly intercommunicative tubular members through which cooling Waterflows, and refractory panels that fit the reticular frame and form thewalls of the hood. The panels are removably secured to the frame and mayindividually be removed and reinstalled when it is desirable to do so.

This invention relates to metallurgical furnaces and,

more particularly, to an exhaust receiving apparatus or hood forreceiving and conducting the hot effluent discharge from a basic oxygenfurnace, and the like. When oxygen is introduced into a basic oxygenfurnace during the steel refining process, great quantities of efliuent,such as gases, fumes, and dust, are produced by the reaction of theoxygen and the hot metal temperature of the eflluent discharge may reach3500 F., or an even higher temperature. During the blowing time, whichmay last from 2022 minutes or longer, the rate of discharge of the gasesmay be in the order of 175,000 cubic feet per minute or more.

An exhaust receiving hood is customarily used to re ceive and conductthe hot efliuent gases from the furnace region to other apparatus whichcleans and treats the gases. Because the gas temperature is so high, itis necessary to cool the hood structure lest it melt under operatingconditions. Heretofore furnace hoods have been provided with waterjacket type shells or envelopes in which water or other cooling fluidflowed and which cooled the hood envelope. Such hoods, however, areheavy and there was always a very present danger of a leak which wouldcause water to enter the furnace.

Other types of hoods have utilized a plurality of adjacentfluid-carrying tubes arranged in much the same fashion as the tubescomprising the steam generator water- Wall in a boiler. In suchinstances, however, the weight of the hood is excessive and that thereis no simple way to make efiective repairs Whenever a leak occurs, hasbeen a serious problem. For these and other reasons, the hoodsheretofore available have not been entirely satisfactory.

In the present invention, a metallurgical furnace hood comprises: areticular frame comprised of spaced apart members; a plurality of panelseach comprised of a grid structure and refractorymaterial secured to thegrid; and means to removably secure the panels to the reticular framethereby forming the efiiuent guiding walls of the hood.

For a further understanding of the present invention and for advantagesand features thereof, reference may be made to the following descriptiontaken in conjunction with the accompanying drawings which show for thepurpose of exemplification, embodiments of the invention.

In the drawings:

FIG. 1 is a schematic side elevational view of one embodiment of anexhaust hood of the present invention;

FIG. 2 is a front elevational view along line lIII of FIG. 1;

FIG. 3 is a perspective View along line IIIIII of FIG. 1;

FIG. 3a is a schematic view of a typical panel securing member;

FIG. 4 is a schematic perspective view of a portion of anotherembodiment of the hood of the invention;

FIG. 5 is a view showing one type of arrangement for securing the panelsof the hood of FIG. 1;

FIG. 6 is a sectional view along line VIVI of FIG. 5;

FIG. 7 is a view showing another type of arrangement for securing thepanels of the hood of FIG. 4; and

FIG. 8 is a view showing another type of arrangement for securing thepanels of the hood of FIG. 4.

In FIGS. 1 and 2, an embodiment of the exhaust receiving apparatus orhood 11 of the invention is shown in operative position relative to abasic oxygen furnace converter 13. The hood 11 includes a reticularstructural frame 15 and a plurality of refractory panels, designatedgenerally as 17; the panels 17 being removably secured to the reticularstructural frame 15.

In FIG. 3, the reticular structural frame 15 is comprised of tubularmembers 19, each member having a hollow head portion 21 and a sternportion 23, and resembling structural Ts in cross-sectional shape. TheT- members 19 are advantageously interconnected in such a manner that acooling fluid, such as water, courses through head portions 21 of thereticular frame 15 to cool the frame. The hollow rectangular shapedtubular head portion 21 and the planar stern portion 23 are, preferably,integrally formed. However, the planar stem portion 23 may be welded tothe hollow head portion 21, about where shown in FIG. 3. The planarstern portion 23 is provided with a plurality of spaced apart holes orapertures 25 which are used to secure the panels 17 to the frame 15.

Referring to FIGS. 1 and 3, the tubular Tee members 19 are connectedtogether to form the reticular frame 15 of the hood 11 which generallyhas a rectangular cross-sectional shape.

The region of the hood 11 nearest the mouth of a basic oxygen converter13 is an entrance region 27 for the substantial volume of gasesemanating from the converter 13. The other end of the hood is an exitregion 31 which is generally connected to other gas receiving apparatus(not shown) for the purpose of conducting the gases away from thefurnace and treating them.

The refractory panels 17 are removably secured to the reticular frame15. As illustrated in FIG. 3, each panel is comprised of a grid 33 ofstructural members, such as the marginal channel members 35 whichencompass the periphery of the panel 17, and the intermediary I- beammembers 37 which are disposed generally transversely of the panel gridand which are secured to the marginal members as by welding, or in anyother suitable manner. Within the spaces of the grid 33, there is asuitable refractory material 39 which may be cast within the grid, or asuitable refractory in the form of bricks; such refractory materialsbeing formed so that the panel has generally planar front and backsurfaces. In the embodiment shown in FIG. 3, the front and back surfacesof the panel 17 are flush with the front and back surfaces of the gridmembers 35, 37. The hood of FIG. 1 comprises a frame 15 and a pluralityof such panels 17. The panels 17 are, of course, so made that they fitin the various shaped openings of the reticular frame 15; that is, somepanels are rectangular, some trapezoidal, and some may be triangular inother applications.

It is a feature of the invention that the panels 17 are readily andquickly removable and replaceable in the frame 15. Generally, the panelscan be quickly and easily removed from the reticular frame to effectrepairs, using suitable auxiliary equipment as required. Such repairsmay be made between successive blowing cycles if con 3. venient, orduring a normal furnace repair and overhaul campaign.

The refractory material, preferably, is capable of withstanding thesevere service conditions including: high ambient temperatures; abrasionby particulate matter in the exhaust gases; oxidation and reductionatmosphere produced within the hood during a complete blowing cycle;water sprays; and the like.

Referring to FIGS. 1 and 3, it will be noticed that the individualrefractory panels 17 are secured in the reticular frame 15 in a novelmanner. Each panel 17 rests upon the stern portion 23 of the adjacentlower tubular member 19, and the marginal channel portion 35 abuts theencompassing vertically disposed tubular head portions 21. The holes orapertures 25 in the stem portions 23 are so located that when a taperedpanel-retaining pin 41, such as is shown in FIG. 3a, is inserted in eachhole they bear against the outer surface of the panel and urge it into afixed position Within the reticular frame. Each tapered panel-retainingpin 41, is provided with a small hole 43 in its smaller end portionwherein a keeper pin 45, such as a conventional cotter pin or the like,may be inserted.

Thus, it is a simple matter to remove each panel by first removing thekeeper pins 45, then removing the panel retaining taper pins 41, andlastly removing the panels themselves by means of suitable auxiliaryhandling equipment. To readily effect the removal of each panel, theremay be provided suitable handling lugs or brackets (not shown) on thegrid structure of the panel to which a crane hook, or other auxiliarylifting equipment, may be attached.

The foregoing has described an embodiment of the novel hood of thisinvention. The hot gases flowing from the basic oxygen furnace orconverter 13 enter the hood 11 at 27 and pass through to auxiliaryequipment where the gases are cooled and otherwise disposed of. As hasbeen pointed out, the temperature of these gases are high, for example3500 F. or higher; the discharge of gases may last from 22-25 minutes;and huge quantities of the gases pass through the hood. During theperiod of operation, water may, if desired, be flowed through the hollowhead portion 21 of the frame members to cool the frame structure.However, since the. panels 17 themselves are of refractory materialwhich is highly resistant to heat, water cooling of the panels isunnecessary.

If after a considerable period of operation one of the panels 17 becomescracked or defective, it is a simple matter to remove the keeper pins 45from the'taper pins 41, and then remove the panel 17. Another panel canthen quickly be inserted in the space in the frame, the retaining pins41 placed in position and the keeper pins 45 inserted in their properplace, locking the retainer pins in place. The hood is again ready foroperation.

The ease with which a panel can be replaced in the present invention ofcourse, is in contrast to the heretofore known methods for repairingother types of hoods where whole sections must be replaced. In somecases even the entire hood structure had to be replaced.

Since Water cooling is required only in some embodiments of the presentinvention and not at all in some other embodiments, describedhereinafter, it is possible with this invention to materially decreasethe weight of the structure and thereby save, for example, in thepumping apparatus that is required to flow water through the usual waterjacket type structure. To this end, FIG. 4 illustrates a portion ofanother embodiment of the hood 11 wherein a structural reticular frame47 is comprised of transversely disposed H-type beams 49 which areconnected to other marginal H-type beams 51 around the perimeter of thehood. A plurality of refractory panels '53 are removably secured in thespaces of the reticular frame 47 thereby forming the walls of theeffluent gas conducting hood.

Each refractory panel 53 is substantially similar to the refractorypanel 35, except that in the embodiment of FIG. 1, a deeper marginalchannel 55 is used around the periphery of the panel and an additionalH-type beam 57 is tranversely disposed within the panel at substantiallythe midpoint of its height. On the web portion of the horizontal H-typebeam 49, there are a plurality, though only one is shown, of cam-leverclamps 59, which are pivotable in a conventional manner and which securethe refractory panel 53 in position to the reticular frame 47. When thecam-lever clamp 59 is in the position, as indicated by solid lines inFIG. 4, the refractory panel 53 is in the secured or locked-in position;and, when the cam-lever clamp 59 is in the position indicated by thedoted lines in FIG. 4, the refractory panel 53 is in the releasedposition, and may be readily removed from the reticular frame 47.

FIGS. 5 and 6 illustrate another embodiment of the hood of the inventionwherein a refractory panel 61 is provided with upwardly and downwardlyextending hasps 63 which are fixed to, as by welding, a marginal channelmember 65 (similar to the marginal channel 35) and which cooperate withoutwardly extending staple members 67, that are fixed to a tubularT'member 69. When such refractory panels 61 are inserted in thereticular frame formed of the tubular Ts 69, the inner surface of thepanels 61 is substantially flush with the interior surface of the frameT members 69.

Each such refractory panel 61 may be removably secured to the reticularframe and maintained in place by means of a keeper pin or wedge-pin 71,such as is indicated in FIGS. 5 and 6.

While not so illustrated in the drawings, the refractory panels 53 mayalso be provided with suitable lifting lugs or brackets whereby eachpanel may be removed from and replaced in the reticular frame 69, in themanner heretofore described.

In FIG. 7, there is illustrated still another embodiment of theinvention, wherein the exhaust hood is comprised of a refractory panel73 and a structural reticular frame 75. The reticular structural frame75' of this embodiment, however, is comprised of H-type structuremembers 77 which, as will be noticed, are not watercooled as are thetubular frame members 15 and 69 of FIGS. 3 and 5. In the embodiment ofFIG. 7, the structural reticular frame 75 is maintained in spaced apartrelation to the heated refractory surfaces of the panels 73, and aretherefore substantially air-insulated from the heat of the refractorypanels.

Each panel 73, in the embodiment of FIG. 7, is comprised of a grid orframe structure 79 which includes marginal channel members 81 that aresimilar to the marginal channel members 35, and H-beam members (orI-beam members) '83 which are similar to, but sub stantially deeperthan, the I-beam members 37 mentioned previously. The refractorymaterial of the panel.

of FIG. 7 is preferably the same as the refractory material 39 of thepanel of FIG. 3. It will be noticed from FIG. 7, however, that thethickness of the refractory panel 73 is only about one-half the depth ofthe H-beam structural member 83.

The structural reticular frame 75 is provided with a plurality (thoughonly one is shown) of outwardly projecting staple-like members 85 whichcooperate with suitably sized apertures 87 in the outwardly facingflange .of the H-beam member 83. Each such staple-like mem- A feature ofthe hood of FIG. 7 is that the structural reticular frame 75 is aircooled by virtue of being spaced apart from the heated surfaces of therefractory panels 73. An additional feature of the hood of FIG. 7 isfound in the smooth interior surface formed by the adjacent abuttingrefractory panels 73. 7

FIG. 8 illustrates a modification of the arrangement for securing thepanels 73 of FIG. 7 to the frame 75; the modification consists inreplacing the staple 85 and apertures 87, S9 of FIG. 7, by a wedge block91 and a coacting keeper wedge 95.

The wedge block 91 is fixed, as by welding, to the horizontal webportion of the H-beam frame member 77, and in one face portion of theWedge block 91 there is a tapered groove 93 which is adapted to receivethe keeper Wedge 95 which has therein an elongated longitudinal slot 97.The wedge block 91 may also have in its bottom a slot 99 for the purposeof allowing water or other liquid, which may accumulate on thehorizontal web of the H-beam member 77, to pass therethrough and notaccumulate on one side of the wedge block. When the panels 73 have beenplaced in the reticular frame in their respective operative positions,the wedges 93 can then be inserted in the slots 97, and urged downwardin the Wedge block 91 to removably secure and maintain the panels 73 inthe frame. Now, in order to remove and replace such panels, it is onlynecessary to insert a suitable tool in the longitudinal slots 97 and pryor urge the keeper Wedges 95 upward and out of the tapered grooves 95.Thereafter, the panels 73 may readily be removed, using suitableauxiliary handling equipment; it being under stood that the panels 73may be provided with suitable lifting lugs or brackets mentionedhereinbefore.

Those skilled in the art will recognize that the refractory panels ofthe present invention can be made in such a manner that the optimumqualities of the refractory materials are fully used, and the panelsperform with the highest efliciency. Moreover, the reticular framestructure is relatively light in weight, is simple to construct, and theuse of the highly refractory materials in the panels results in anexhaust hood that is less expensive and more effective.

The panels of the present structure, also, can be readily and quicklyrepaired and maintained with a minimum of lost time and expense; thereWill also be a minimum of lost furnace time during regular maintenancecampaigns. That such economies are effected in the hood of the presentinvention is due to the panels being readily and quickly removable andreplaceable from the reticular frame.

The hood structure of the present invention, moreover, requires aminimum of water cooling. Only the frame structure in the embodiments ofFIGS. 3 and 5 are water cooled; in the other embodiments no watercooling is required. That such a hood represents a material andsignificant saving in initial investment and operating expense should beevident to those skilled in the art.

Although the foregoing describes with a certain degree of particularitya preferred and other embodiments of the invention by way of an example,it is understood that the invention is not so limited, but is defined bywhat is hereinafter claimed.

I claim:

1. A hood for a metallurgical furnace comprising:

(a) a reticular frame disposed relative to said furnace including aplurality of spaced apart fluid conductive interconnected members;

(b) a plurality of panels of refractory material mounted in saidreticular frame and forming the efiiuent conducting walls of said hood;

(c) means to circulate coolant in the fluid conductive members of saidframe structure; and

(d) means to removably secure in operative positions said panels to saidreticular frame.

2. A hood for a metallurgical furnace comprising:

(-a) a reticular frame including a plurality of spaced apart fluidlyintercommunicative tubular members wherein a cooling medium flows andmaintains said frame cool;

(b) refractory panels mounted to said reticular frame forming theefiiuent conducting walls of said hood, said panels being comprised ofgrid supported refractory material; and

(c) means for removably securing said panels in operative relation tosaid reticular frame.

3. The invention set forth in claim 2 wherein:

(a) said fluid conductive tubular members are provided with means onwhich said panels are supported.

4. The invention set forth in claim 3 wherein:

(a) said panel supporting means has apertures therein;

and

(b) means adapted for inserting in said apertures are provided wherebysaid means coacts With said frame and panel to removably secure saidpanel in operative position to said frame.

5. A hood for a metallurgical furnace comprising:

(a) a reticular frame including a plurality of spaced apartinterconnected members;

(b) refractory panels comprised of a grid and refractory materialconnected thereto adapted for mounting to said frame and forming theefiiuent conducting walls of said hood;

(c) hasps mounted on each said panel;

(d) eyes mounted on said frame for cooperation with said hasps; and

(e) means for securing said cooperative hasps and eyes whereby eachpanel is removably secured to said frame.

6. The invention of claim 5 wherein:

(a) said eyes have apertures therein; and

(b) a wedge is insertable in said eye whereby said hasp and the panelconnected thereto is urged into operative position relative to saidframe to form the efliuent conductive walls of said hood.

7. A hood for a metallurgical furnace comprising:

(a) a reticular frame including a plurality of spaced apartinterconnected members;

(b) an eye fixed to said frame and projecting therefrom;

(c) refractory panels comprised of a grid and refractory materialconnected to said grid adapted for mounting to said frame and formingthe efiiuent conducting walls of said hood, at least one said gridmember of each panel having an aperture therein adapted to cooperatewith an eye fixed to said frame; and

(d) means cooperating with the aperture in said eye to urge said panelinto a removably secured relation to said frame.

8. The invention set forth in claim 7 wherein:

(a) said eye has therein an aperture; and

(b) a wedge is inserted in the aperture of said eye for removablysecuring said panels in operative position relative to said frameforming the effluent conductive walls of said hood.

9. The invention set forth in claim 7 wherein:

(a) said frame is spaced and maintained apart from the refractory panelsurfaces whereby an air-insulating space is created between said frameand the refractory surfaces of said panels.

10. A hood for a metallurgical furnace comprising:

(a) a reticular frame including a plurality of spaced apartinterconnected members;

(b) refractory panels comprised of a grid and refractory materialconnected thereto adapted for mounting to said frame and forming theeffluent conducting walls of said hood;

(c) wedge blocks mounted to said frame and having in one surface atapering groove;

(d) means to position a portion of said panel between the groovedsurface of said Wedge blocks and said frame; and

(e) a wedge disposed in said tapered grooves cooperating with said Wedgeblocks and said panel to urge said panel against said frame whereby saidpanel is removably secured in said frame.

11. A hood for a metallurgical furnace comprising:

(a) a reticular frame including a plurality of spaced apartinterconnected members;

(b) refractory panels comprised of a grid and refractory materialconnected thereto adapted for mounting to said frame and forming theeffluent conducting Walls of said hood; and

(c) pivotal cam levers mounted to said frame;

8 ((1) means to position a portion of a panel between said cam lever andsaid frame whereby when said cam lever is actuated said panel is wedgedagainst said frame and said panel is removably secured in said frame.

References Cited UNITED STATES PATENTS 3,257,106 6/1966 Preston 26636FOREIGN PATENTS 793,038 4/ 1958 Great Britain. 812,274 4/ 1959 GreatBritain.

15 CHARLES I. MYHRE, Primary Examiner.

1. A HOOD FOR A METALLURGICAL FURNACE COMPRISING: (A) A RETICULAR FRAMEDISPOSED RELATIVE TO SAID FURNACE INCLUDING A PLURALITY OF SPACED APARTFLUID CONDUCTIVE INTERCONNECTED MEMBERS; (B) A PLURALITY OF PANELS OFREFRACTORY MATERIAL MOUNTED IN SAID RETICULAR FRAME AND FORMING THEEFFLUENT CONDUCTING WALLS OF SAID HOOD; (C) MEANS TO CIRCULATE COOLANTIN THE FLUID CONDUCTIVE MEMBERS OF SAID FRAME STRUCTURE; AND (D) MEANSTO REMOVABLY SECURE IN OPERATIVE POSITIONS SAID PANELS TO SAID RETICULARFRAME.